For those who can’t go a morning without their cup of joy, many are now a-buzz about the benefits that come from Bulletproof coffee: an old world tradition that has re-emerged as a potent performance enhancer.

The drink was coined by Dave Asprey, an American technology entrepreneur, who claims to have lost 100 pounds by eating a high-fat, low-carbohydrate diet. His inspiration for Bulletproof coffee came from his experience of drinking yak tea with butter in the high elevations of Tibet. Thousands of people credit this high-fat, calorie-dense breakfast replacement with increased energy levels, better focus and major weight-loss results.

Butter coffee. Reportedly, it’s made by taking brewed coffee and blending it with around 80 gramsof butter, which is about 3/4 of a stick!

And, this concoction is being touted as a way to give dieters energy and promote weight loss.

Bulletproof Coffee is frothy, oily, fatty coffee. It’s essentially putting oil and fat (in the form of grass-fed butter, typically) in your coffee. And although it’s currently quite trendy, the truth is that some cultures have been doing this for centuries. Spiced butter coffee is a longstanding Ethiopian tradition!

Asprey says that the specific kind of butter (grass-fed and unsalted, or ghee) and quantity (2 tbsp. max, once you build up to that) will put your body into fat-burning mode for the rest of the day. He compares it to other healthy fats (like the kind in avocados and nuts), which optimize cholesterol, and don’t raise it.

Keep in mind that Bulletproof coffee itself is meant to be a meal replacement, so you are only supposed to drink the coffee for breakfast, not have it alongside other healthy food.

When you are consuming butter, to have the proper health benefits, it really should be organic and grass-fed. Butter is an excellent source of vitamins, including Vitamins A, E & K.

Fans are even drinking it as a meal substitute. They claim the combination of ingredients makes it the perfect breakfast-in-a-cup, giving you a prolonged energy hit, which sharpens your focus, burns calories, strips you of excess body fat and leaves you feeling full until lunchtime.

The downside is that the cloying texture makes it an acquired taste and those trying it for the first time often complain of nausea and diarrhea.

The theory is that if you’re not filling your diet with carbohydrates (such as sugar, bread and pasta), your body will use fat as fuel instead. This is called ‘ketosis’. The ketogenic process is what makes Atkins and other low-carbohydrate diets work, but it is frowned upon by conventional weight-loss experts in this country, who say that low-carbohydrate diets can lead to headaches, muscle cramps, general weakness and digestive problems.

Health mogul and naturopath Dr. Andrew Weil says this buttery coffee is “a worthwhile experiment for the sake of both taste and health if you are inclined to try it.” He recommends using fats in moderation as part of an anti-inflammatory diet, saying “blending a tablespoon or so of high-quality, unsalted, organic butter into your morning coffee or tea is unlikely to do you any harm.”